ads user help me

i have serious problem wih ATF36077 ,condition of bias vds=1.5,ids=10 ma,
vgs=-.2,how?,i obtain the vol of vgs,it was so small,also any buddy give me the wquastions of calculation of rs and rd
thanks so much

Have a look at hxxp://www.applet.cz/~ulcak/lna.htm. (replace xx -> tt)
Bye
Mazz

hi mazz thanks for reply but i see tha site bofore if u have any paper about supply of atf36077 i will be thanked,how i get vgs=-.2 are u see it is impractical

if you realy need that value (very seriously), you may use 16bit D/A.

Use an active biasing scheme, it will fix the drain current and adapt the VGS to it's purpose!

any buddy have that design or ideas about biasing pls upload it or reply me at pm
regards

There is an IC from infineon for an active bias circuit.
http://www.infineon.com/cgi/ecrm.dll....jsp?oid=13786
i am not sure that you can use -0.2 v or not.

Put a 20 ohm resistor in series with the source lead to ground, DC ground the gate with an inductor, put 1.7 volts on the drain. Assuming a drain current of 10mA, the SOURCE to GROUND voltage is 0.2 volts AND thus the voltage from GATE to SOURCE is -0.2V (since the gate is grounded). The DRAIN to SOURCE voltage will be 1.5V (1.7V - 0.2V). Try it.

Check this out, too:

h**p://www.applet.cz/~ulcak/lna.htm

hi i avoid connect source to bias,here my design ,is that design correct,i apporximate that drain current equal source cuurent and gate ground voltage=-.2 plus voltage drop on source resistance